You can modify the appearance of the XY and histogram plot axes by changing the parameters that control the labels, scale, range, numbers, and major and minor rules. For each type of plot (solution XY, file XY, residual, histogram, etc.), you can set different axis parameters in the Axes panel (Figure 28.8.11). Note that the title following Axes in the panel indicates which plot environment you are changing (e.g., the Axes - Solution XY Plot panel controls axis parameters for solution XY plots).
To open the Axes panel for a particular plot type, click the Axes... button in the appropriate panel (e.g., the Solution XY Plot, File XY Plot, or Residual Monitors panel).
Using the Axes Panel
The Axes panel allows you to independently control the characteristics of the ordinate ( axis) and abscissa ( axis) on an XY plot or histogram. To set parameters for one axis or the other, you will follow the procedure below:
Your changes to the axis attributes will appear in the graphics window the next time you generate a plot.
Changing the Axis Label
If you want to modify the label for the axis, you can do so by editing the Label text field in the Axes panel.
Changing the Format of the Data Labels
You can change the format of the labels that define the primary data divisions on the axes using the controls under the Number Format heading in the Axes panel.
Choosing Logarithmic or Decimal Scaling
By default, decimal scaling is used for both axes (except for the axis in residual plots, which uses a log scale). If you want to change to a logarithmic scale, turn on the Log option in the Axes panel. To return to a decimal scale, turn off the Log option. Note that when you are using the logarithmic scale, the Range values are the exponents; to specify a logarithmic range from 1 to 10000, for example, you will specify a minimum value of 1 and a maximum value of 4.
Resetting the Range of the Axis
By default, the extents of the axis will range from the minimum value plotted to the maximum value plotted. If you want to change the range or extents of the axis, you can do so by turning off the Auto Range option in the Axes panel and setting the new Minimum and Maximum values for the Range. This feature is useful when you are generating a series of plots and you want the extents of one or both of the axes to be the same, even if the range of plotted values differs. (For example, if you are generating plots of temperature on several different wall zones, you might want the minimum and maximum temperature on the axis to be the same in every plot so that you can easily compare one plot with another. You would determine a temperature range that includes the temperatures on all walls, and use that as the range for the axis in each plot.)
Controlling the Major and Minor Rules
FLUENT allows you to display major and/or minor rules on the axes. Major and minor rules are the horizontal or vertical lines that mark, respectively, the primary and secondary data divisions and span the whole plot window to produce a "grid.'' To add major or minor rules to the plot, turn on the Major Rules or Minor Rules option. You can then specify a color and weight for each type of rule. Under the Major Rules or Minor Rules heading, select the desired color for the lines in the Color drop-down list and specify the line thickness in the Weight field. A line of weight 1.0 is normally 1 pixel wide. A weight of 2.0 would make the line twice as thick (i.e., 2 pixels wide).